From owner-freebsd-isp Sun Aug 23 18:39:32 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA22957 for freebsd-isp-outgoing; Sun, 23 Aug 1998 18:39:32 -0700 (PDT) (envelope-from owner-freebsd-isp@FreeBSD.ORG) Received: from enya.hilink.com.au (enya.hilink.com.au [203.8.14.116]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA22939; Sun, 23 Aug 1998 18:39:25 -0700 (PDT) (envelope-from danny@enya.hilink.com.au) Received: from localhost (danny@localhost) by enya.hilink.com.au (8.8.8/8.8.7) with SMTP id LAA12612; Mon, 24 Aug 1998 11:39:11 +1000 (EST) (envelope-from danny@enya.hilink.com.au) Date: Mon, 24 Aug 1998 11:39:11 +1000 (EST) From: "Daniel O'Callaghan" To: "Jonathan M. Bresler" cc: isp@hub.freebsd.org Subject: Re: [Q] what happens when 1 of N nameservers dies? In-Reply-To: <199808212326.QAA13587@hub.freebsd.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Fri, 21 Aug 1998, Jonathan M. Bresler wrote: > what happens when a domain with N nameservers loses one? > > let abc.org have 3 domain nameservers ns1.abc.org, ns2.abc.org, > and ns3.abc.org. all are pointed to by the Internic. > one dies. a person/program at another domain does a lookup > on a host in abc.org. > > what happens? > > do 1/3 of the lookups return "host unknown"? > does the resolver try one nameserver and if it does not > receive a response try another? If deadns.abc.org is totally dead, it will time out and another NS will be queried. If deadns.abc.org is no longer secondarying abc.org, it will say "Ask these three nameservers (and list itself)" by recursing to the root nameservers. If deadns.abc.org still knows that it is an ns for abc.org, but it has forgotten all data because it could not reach the primary for 30 days and the data expired, then it will say something like "Nonexistent host - server failed." Danny To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message